U.S. Pat. No. 4,729,077 to Gordin shows a luminaire assembly for high power, high intensity lighting applications, comprising a luminaire fixture to which are operatively mounted a reflector having an innermost center portion and an outermost peripheral portion, and a single high power, high intensity, lamp to which is operatively supplied electrical power to produce a light beam. An adjustable lamp positioning means is mounted between the luminaire fixture and the lamp. The light positioning means is power operated to vary the width of the light beam (beam angle) produced by the lamp between a narrow or spot beam and a wide or flood beam, according to choice, by moving the lamp relative to its reflector. The term "beam angle" is known in the art to mean the included angle between those points on opposite sides of the beam axis at which the luminous intensity from a light source is 50% of maximum.
U.S. Pat. No. 4,675,794 to Fink shows a high intensity lamp fixture with a mounting mechanism within the lamp fixture that allows movement of the light source within the fixture relative to a reflector surrounding the light source to allow adjustment of the beam of light emanating from the light source. Fink's apparatus includes a housing surrounding the light source, a generally parabolic reflector, and an adjustable lamp socket support mechanism for positioning the lamp socket relative to the parabolic reflector. Fink's preferred adjustment mechanism is a manually operable screw mechanism for adjusting the position of a single support bracket and lamp socket to a desired position relative to the reflector so that a single beam of light from a single light source or lamp in the one socket may be controlled between a wide or flood beam and a narrow or spot beam.
U.S. Pat. No. 4,967,325 to Shiau shows a flashlight comprising a bead assembly rotatably engaged with a barrel. A lamp base is fixed inside the head assembly. When the head assembly is rotated relative to the barrel, a flashlight bulb fixed to the lamp base moves axially away from or toward a lens attached to the head assembly, thus varying the focusing distance of the bulb and providing a spot beam or flood beam, as desired.
U.S. Pat. No. 4,386,391 to Gulliksen shows a luminaire apparatus with multiple light sources, including method and means for providing individual adjustment of the beam angle for each energized light source. The individual focus adjustment for each energized light source is accomplished by individually moving a selected light source along a focal axis of the luminaire apparatus to provide a spot beam or flood beam, as desired.
The prior art known to applicant shows it old to change the beam angle of a single light source by moving the light source relative to the reflector surrounding the light source or lamp but, to applicant's knowledge, nothing in the prior art suggests any method or means for simultaneously changing the beam angle of all of the light sources in an array of multiple light sources.